I am getting very interested in the history of pool in America. I'm kind of curious about where most folks think the modern game as we know it evolved the most.

There was Michael Plelan in New York in the mid-19th Century, and there was plenty of billiards in Chicago way back when. But if you could put a pin in a map of the US, where would you put it that, in your opinion, would best be described as the epicenter that post-WWII pocket billiards radiated out from?